Method of bleaching oils and fats



Patented May 16, 1939 2,158,163 METHOD OF BLEACHING OILS AND FATS Walter M. Urbain and Lloyd B. Jensen, Chicago,

111., assignors tion, Chicago, 111-,

5 Claim!- (CL 260-423) This invention relates to the treatment 01' fats and oils.

It is desirable in the preparation of fats and oils to produce products which are relatively light 5 in color.

The present invention contemplates the employment of the combination of hydrogen peroxide and nitrogen salts as a bleaching agent. We have found that this combination is peculiarly e1- iective in bleaching edible fats and oils. It may be that the utility of such mixtures resides in the formation of pernitric acid (31104). In bleaching fats and oils in accordance with the present invention, we prefer to employ nitrltes,

sodium nitrite being particularly efl'ective.

The utility of the present invention will be apparent by reference to Table I and Table II giving the results of the treatment of a tallow known as /S/ tallow.

The tallow was first cleaned by an acid wash followed by agitation with fullers earth and a small amount of decolorizing carbon, after which the cleaned tallow was filtered. In bleaching the fat, the hydrogen peroxide and sodium nitrite were dissolved in about 10 cc. of water which was added to 100 gm. of the fat which had been previously heated to about 60 C. and was in liquid condition. The mixture was vigorously agitated for a few minutes and then was allowed to stand for several hours at a temperature of from C. to C.

Bleaching action from the combination of hydrogen peroxide and sodium nitrite is apparent 5 in a few minutes, although it is preferable to let 3 the mixture stand for several hours to render reasonably certain that all bleaching value of the bleaching agents is obtained.

0 Table II indicates the results of an experiment on another batch of the same /S/ tallow.

to Industrial Patents Corporaa corporation of Delaware No Drawing. Application December 24, 1936,

Serial No.

Table II Gm.hy- Gm. FAG Sample drogen sodium rea peroxide nitrite N. D. 5

tables that the combination of hydrogen peroxide and sodium nitrite gives results greater than the sum of the results of sodium nitrite and hydrogen 15 peroxide when used separately, sodium nitrite when used alone being ineilective.

Sample 4 of Table I was converted to the sodium soap and the fatty acids liberated subsequently with sulphuric acid.

The reading of the 20 N. D. T. 21 was unchanged indicating no change of color upon saponiflcation.

The present invention provides a simple, in-

expensive and effective method for bleaching fats and oils.

In the claims, the term oil is used in the. broad sense to include both fats and oils separately or in mixtures.

We claim:

1. The method of treating oil which comprises adding thereto hydrogen peroxide and a nitrite.

2. The method of treating oil which comprises adding thereto hydrogen peroxide and sodium nitrite.

to bleach.

4. The treatment of oil which comprises add- 4 ing from 0.3 per cent. to 1.5 per cent. hydrogen peroxide and from 0 .4 per cent. to 2.0 per cent.

sodium nitrite to the oil.

5. The treatment of oil which comprises adding from 0.3 per cent. to

peroxide and from 0 sodium nitrite to the 1.5 per cent. hydrogen 4 .4 per cent. to 2.0 per cent. oil, agitating the mixture to secure intimate admixture, and permitting the oil to bleach.

WALTER M. URBAIN. lo LLOYD B JENSEN. 

